Description
SunRace CS-R91 9-speed cassette
The SunRace CS-R91 9-speed cassette is a lightweight road-focused option with a practical 11-28T range, ideal for city, e-bike, and race bikes. It belongs to the R9 group and fits standard HG-Spline freehub bodies, so it installs easily on most 9-speed road and fitness wheels. With an alloy lockring, gray spacer, and nickel finish, it combines a clean look with improved corrosion resistance. At just 264 g, it helps keep rotating mass low for quicker acceleration and a more responsive ride feel.
Performance and gearing
This cassette uses an 11-12-13-14-16-18-21-24-28T progression, giving tight gear steps for steady cadence control. Riders can fine-tune effort on flats, rolling terrain, and moderate climbs without big jumps between gears. The close-ratio layout pairs well with compact or mid-compact chainsets, offering enough top-end speed for fast descents while keeping low gears effective in traffic or on short rises. That makes the CS-R91 well suited to training rides, daily commuting, and entry-level racing where smooth power delivery matters.
Build and compatibility
The CS-R91 uses steel sprockets shaped with SunRace’s Super Fluid Drive technology, which guides the chain cleanly between cogs for quiet, precise shifting even under load. The cassette’s lightweight yet durable construction stands up to regular road use, including e-bike duty. It works with Shimano HG-compatible 9-speed drivetrains, so it fits many common city, fitness, and road bikes using Shimano or SRAM 9-speed shifters and derailleurs. For riders replacing a worn cassette, the SunRace CS-R91 offers an easy upgrade that improves shifting feel while keeping the bike light, efficient, and ready for everyday riding.
